Iodphors are water-soluble physiologically-acceptable complexes of iodine with organic carriers. The general class of organic iodophors comprises two distinct polymer groups, namely the non-detergent, nonionic and non-surface active polymers, and the detergent/surface-active polymers which includes both nonionic, anionic and cationic surface-active polymers.
The most commonly used organic iodophor is polyvinylpyrrolidone-iodine. This is also known as povidone-iodine, and will be referred to as such hereafter.
Povidone-iodine and its preparation has been described in U.S. Pat. No. 2,739,922. For many years, this was substantially the only non-detergent, nonionic iodophor which has been found to be suitable for germicidal action in man and animals, as well as in environmental uses.
U.S. patent application Ser. No. 638,558, filed Aug. 7, 1984 describes a new nonionic, non-surface active iodopor which is a complex of iodine with polydextrose and which is herein referred to as polydextrose-iodine.
Polydextrose, which is described in U.S. Pat. Nos. 3,766,105 and 3,786,794, is a white to tan powder occurring in both water soluble and water insoluble forms and having an average molecular weight of about 1,500 to 36,000, with the water soluble polydextrose having an average molecular weight of about 2,500 to 18,000, and water insoluble polydextrose having an average molecular weight of between 6,000 to 36,000.
The average molecular weight of commercially available polydextrose is 1,500, ranging from 162 to approximately 20,000. This molecular weight range ensures a high degree of water solubility and relatively low viscosity. The molecular weight range for commercially available polydextrose is:
______________________________________ MOLECULAR WEIGHT RANGE PERCENT ______________________________________ 162-5,000 88.7 5,000-10,000 10.0 10,000-16,000 1.2 16,000-18,000 0.1 ______________________________________
The polydextrose-iodine complexes of U.S. patent application Ser. No. 638,588 contain up to 20% by weight of iodine, generally between 1-20%, preferably 2-16% and most preferably 2-10%.
Both the povidone-iodine and the polydextrose-iodine complexes have good microbicidal activity and can be used for humans, animals and environmental treatment compositions. However, improvements in these iodophors has been sought, particularly from the standpoint of speed of action, that is speed of first kill, and duration of action, that is long-lasting kill.